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Lead-free electronic products is the development trend of green electronic assembly, the promotion and application of lead-free solder, there are still more difficulties. The main problem is the poor wettability, high melting point, oxidation, and the application of flux, the the traditional flux has been difficult to adapt to the needs of lead-free soldering processes. This paper mainly discusses cored solder wire with a high temperature solid flux formulations, the flux of the active ingredient, carriers and surface active agents screening, developed excellent flux cored solder wire with solid. Cored solder wire with the flux of the development process, first identified using different organic complex ideas, choose the active ingredient, carrier and surfactant. Corrosion weightlessness experiment, surface insulation resistance test and spatter test to determine the selection of higher activity dibasic acid adipic acid and sebacic acid as the the composite active ingredient of the flux, stearic acid, rosin and polyethylene glycol as the flux vector. Select the anionic sodium dodecyl sulfate, cetyltrimethylammonium bromide cationic and non-ionic OP-10 as a surface active agent. Found through a different proportion of the active agent, spreading experiment, the proportion of adipic acid and sebacic acid is 4:1 maximum spreading area, good wettability, and with the reduction of the adipic acid, spreading the change of area small trend. Stearic acid, rosin, and polyethylene glycol in a ratio of 2:1:2 is demonstrated when a good wettability of different carrier component orthogonal test. Orthogonal test of the surfactant cetyl trimethyl ammonium bromide greatest impact, spreading area becomes large with the increase of the added amount. Cetyl trimethyl ammonium bromide is a halogen-containing, consider the optimization of the surface active ingredient. And determining the reduction of the content of the cetyl trimethyl ammonium bromide, adding OP-10. Determined by the surface active ingredients to optimize the flux of the final ingredient of the flux, determine the composition of the flux is adipic acid and sebacic acid (4:1), stearic acid, polyethylene glycol, and the rosin (2:1:2) , the composition of the surfactant OP-10 (0.9%) and cetyl trimethyl ammonium bromide (0.3%). Prepared using the flux-cored solder wire welding solder shape rules full 30 minutes in a 170 ° C high temperature environment, no discoloration, to meet the need for welding of the high-temperature electronic devices.
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